Progestin-Only Hormonal Methods (Mini-Pills, Implants, and Shots)

Looks at progestin-only hormonal methods (mini-pills, implants, and shots) to prevent pregnancy. Includes generic and brand names such as medroxyprogesterone acetate (Depo-Provera). Covers how well they work and side effects.

Progestin-Only Hormonal Methods (Mini-Pills, Implants, and Shots)


Oral contraception

Generic Name Brand Name
norethindrone Micronor, Nor-QD


Generic Name Brand Name
etonogestrel Implanon, Nexplanon


Generic Name Brand Name
medroxyprogesterone Depo-Provera

How It Works

birth control methods, including pills (called
"mini-pills"), implants, and shots, prevent the ovaries from releasing an egg
(ovulation), thicken mucus at the cervix so sperm cannot enter the uterus, and
in rare cases, prevent a fertilized egg from implanting in the uterus.

Birth control mini-pills

Progestin-only mini-pills
come in a monthly pack. To be effective, the pills must be taken at the same time each day. If you take a pill more than 3 hours late:

  • Take it as soon as you remember even if that means you will take 2 pills in one day. Use another method
    of birth control for the next 48 hours to prevent pregnancy.footnote 1
  • Consider using
    emergency contraception if you have had sex in the past 3 to 5 days.


The progestin-only implant releases hormones that prevent pregnancy for 3 years. The actual implant is a
thin rod about the size of a matchstick. This is inserted under the skin on the
inside of the upper arm.

  • The implant is a highly effective method of birth
  • The implant must be inserted and removed by a trained health


The birth control shot, such as Depo-Provera, is effective
for 12 to 13 weeks.

Why It Is Used

Progestin-only mini-pills, implants,
and shots are good choices for women who:

  • Are breastfeeding. The mini-pill is a good choice for
    breastfeeding mothers. It is very low-dose and does not affect the milk
    supply. Breastfeeding further reduces the chance of pregnancy.
  • Need short- or long-term birth control that can be stopped at any
    time. (But it may take from 12 weeks to 18 months to become pregnant after stopping the birth control shot.)
  • Prefer a form of birth control that does not interfere with
    sexual spontaneity.
  • Cannot take estrogen, including those who smoke and are older
    than 35; have long-standing, poorly controlled
    diabetes; have
    heart disease; have problems with
    blood clots; or have
    high blood pressure.
  • Have
    migraine headaches with
    auras, or women whose migraines get worse when taking
    the estrogen in combination birth control pills.
  • Have heavy, painful menstrual periods. Progestin reduces heavy
    bleeding and cramping.
  • Have
    anemia from heavy menstrual bleeding.
  • Have
    sickle cell disease. Women with sickle cell disease
    may have fewer problems from their disease when using the birth control

How Well It Works

Shots and implants are highly
effective methods of birth control.

Progestin-only mini-pills are
very effective, but combination hormone pills are even more effective. Also,
the mini-pill has to be taken at the same time every day to work

The shot

This method is highly effective,
unless you fail to get a shot after 3 months.footnote 2

  • Typical use: Among all Depo-Provera users, 6 women out of 100
    become pregnant each year.
  • Perfect use: Of women who get their shots on schedule, fewer than 1 out of 100 become pregnant each year.

Progestin mini-pill

This method is very effective,
but you must take the mini-pill at the same time every day.footnote 2

  • Typical use: Among all mini-pill users, 9 women out of 100
    become pregnant each year.
  • Perfect use: Of women who take every mini-pill on schedule,
    fewer than 1 out of 100 become pregnant each year.


This method is extremely effective and
lasts for 3 years.footnote 2

  • Typical use and perfect use are the same for this method. Fewer than 1 woman out of 100 has an unplanned pregnancy.

Medicines that can interfere with hormonal birth control

Some combinations of medicine may affect the birth control hormones in
your body, making them too strong or too weak. This may increase your chance of
becoming pregnant. Or a new medicine may be less likely to work because you
have birth control hormones in your body. Talk with your doctor or pharmacist
to make sure that the medicines you take are not causing problems when you are
using hormonal birth control.

Side Effects

Most side effects of the progestin-only
birth control methods go away after the first few months of use. Side effects

  • Irregular menstrual cycles.
  • Spotting or bleeding between menstrual periods.
  • Sore breasts.
  • Headache.
  • Nausea.
  • Dizziness.
  • Bloating or weight gain, especially with the birth control shot.
  • No menstrual periods. Although mini-pill use can stop periods,
    the shot is most likely to do so.

Less common progestin side effects include
depression and darkening of the skin on the upper lip,
under the eyes, or on the forehead (chloasma).

Risks of the shot

Bone thinning. Use of the shot for 2 or more years can cause bone loss,
which may not be fully reversible after stopping the medicine.footnote 3

For teens, bone loss from the shot is a
concern. Teens are normally building bone mass as they grow. This is why it is
very important for teens to get enough calcium and vitamin D when using
the shot. A small study among teens showed that bone loss from the shot
was reversed after the teens stopped getting the shots.footnote 4 Talk to your doctor about your risk if you have been using
the shot for longer than 2 years.

Progestin risk after having gestational diabetes

Breastfeeding women can use the mini-pill or shot without worrying about
effects on their milk supply or the baby. But using progestin-only birth
after having
gestational diabetes appears to make it more likely
that you will develop
diabetes.footnote 1

See Drug Reference for a full list of side effects.
(Drug Reference is not available in all systems.)

What To Think About

Progestin-only mini-pills may not
be as effective if you are vomiting or have diarrhea. Use another method of
birth control for 7 days after vomiting or diarrhea, even if you have not
missed any pills.

Complete the new medication information form (PDF) ( What is a PDF document? ) to help you understand this medication.



  1. Raymond EG (2007). Progestin-only pills. In RA Hatcher et al., eds., Contraceptive Technology, 19th ed., pp. 181–191. New York: Ardent Media.
  2. Trussell J, Guthrie KA (2011). Choosing a contraceptive: Efficacy, safety, and personal considerations. In RA Hatcher et al., eds., Contraceptive Technology, 20th ed., pp. 45–74. Atlanta: Ardent Media.
  3. U.S. Food and Drug Administration (2004). Depo-Provera contraceptive injection (medroxyprogesterone acetate injectable suspension). Safety Alerts for Human Medical Products. Available online: ://
  4. Scholes D, et al. (2005). Change in bone mineral density among adolescent women using and discontinuing depot medroxyprogesterone acetate contraception. Archives of Pediatrics and Adolescent Medicine, 159(2): 139–144.


ByHealthwise StaffPrimary Medical Reviewer Sarah Marshall, MD - Family Medicine Adam Husney, MD - Family Medicine Kathleen Romito, MD - Family Medicine Specialist Medical Reviewer Rebecca Sue Uranga, MD - Obstetrics and Gynecology

Current as ofNovember 21, 2017